POLYPODIUM. 45 



fication is composed of bunches of clus- 

 tered thecse, green when young, and 

 ripening into brown. April. Deciduous. 

 Common in marshes and damp situations. 

 Easy of cultivation. Hardy. Best trans- 

 planted large. Though wanting in the 

 waving varied tracery of outline in the 

 pinnule, which favourably distinguishes so 

 many of the tribe, yet justly admired for 

 the contrast it affords by its fine bold 

 appearance. 



POLYPODIUM. 



Sori on the back, in round masses, perfectly 

 naked. No Indusium. Root creeping in all. 



POLYPODIUM ALPESTRE. (Alpine Polypody.} 

 Fig. 13. From 12 to 18 inches. Growing 

 in masses. Frond narrow and tapering 

 to both ends. Pinnae opposite below, more 

 alternate above. Pinnules very thin and 

 delicate, longish, succulent, hardly-stalked, 

 toothed, and somewhat roundly divided, 

 throughout. Sori towards the top of the 

 frond, forming two rows along the pinnule, 

 one little cluster being in each division of 

 it. End of May. Deciduous. Only yet 

 found in one or two places in the High- 



